Underlay for printing plates or forms



Nov! ^9 S. E. DITTMAN UNDERLAY FOR PRINTING PLATES 0R FORKS 2 Sheets-Sheet 1 Filed April 19. 1923 Nov., 16 1926. 1,607,190

s. E. DHTMAN UNDERLAY Ffm PRINTING PLATES on Forms FnedrApril 19, 192s 'z shuts-sneu a i of'one of the underlay sheets.

Patented Nov. 16, 1926.

UNITED sATEs PATENT. OFFICE.

SAMUEL E. DITTMAN, OF CHICAGO, ILLINOIS; WILLIAM DITTMAN ADMINISTRATOR 0F SAID SAMUEL E. DITTMAN, .'DECEASED.

UNDERLAY-FOR PRINTING PLATES OR FORMS.

Application led April 19, 1923. Seria1`N0. 633,212.

My invention relates to an underlay for building up or leveling printing plates 0r forms and which forms, after the plates or forms have been leveled or built up, a seat or backing for the plates or forms.

Une feature of my invention resides in the provision of an underlay for leveling or building up printing plates or forms without injuring the printing faces thereof and which, after the plates or forms are leveled or built up, provides 'a resilient seat or backing therefor whereby to afford a resilient printin contact. The underlay is particularly a apted for use directly en printing presses and affords an extremely slmple and effective means for building up or leveling a printingplate or form, its use materially decreasing the time and skill ordinarily required for make ready and at `the same time affording a much to be desired resilient printing contact.

Another feature resides in the provision of prepared underlay sheets of the above described character which are adapted to be conveniently manufactured in large quantities and shipped and stored with a view toward commercial practicability and convenience to the consumer.

With these features and others, hereinafter appearing, in view the invention consists in the matters hereinafter fully described with reference to the accompanying drawings and more particularly pointed out in the claims.

In the said drawings- Figure 1- is an enlarged partial face View of a prepared underlay sheet.

Figure 2 is a section on the line 2 2 of- Fig. l.

Figure is an enlarged partial face view of another form of sheet. f

Figure 4 is a section on theline 4-4 of Fig. 3. i Figure 5 is an enlarged partial face vlew of another form of sheet.

Figure 6 is a section on Fig. 5.l I

Figure 7 is an exaggerated sectlon of a plate and a prepared underlay sheet'of the material on a printing press bedafter the plate -hasbeen leveled or builtup by means the line 6 6 of Figure 8 isV an-enlarged partial face view of another form of underlay sheet.

Figure 9 1s a sectionfon the line 9-9 of Fijg, 8. ike characters of reference indicate like parts 1n the various views.

The underlay material of my invention is or form. The underlay material is prefer-` ably applied to the back of the-plate in a. displacement space providing pattern whereby thc necessary pressure is decreased, whereby the displacement is localized, and whereby no portion of the plate-is subjected to undue pressure. The pattern of the underlay material is preferably of uniform thlckness and provides uniform displace ment space for obvious reasons. A material which has these characteristics and which functions very well when applied to the back of a plate or form in a displacement space providing pattern consists of four parts ilexible glue, four parts glycerine, one half part paraihne wax, one half part rubber cement, and one part water boiled together, the most important ingredients being exible glue, glycerine, wax and water mixed together in suitable uantities and under suitable conditions to orm the material having the above set forth characteristics.

Referring to the drawings, Figures l-G' .suitable material, such as cloth, and support the material inlayer form and, protect 1t.

prevent atmospheric conditions from affectmg the material. Figures 8 and 9 show a preparedsheet in which lonly vone* sheet 2 of vThe paper slieetsr2 are preferably oiled` to paper or suitable material is adhered to a face 'of the pattern of material.

In the use of the prepared sheets to build Y 4sheet in desired position on the bed 4f of a ltr printing press and subjecting them to pressure between the bed and impression element of the press. The material permanently displaces under the pressure and conforms the face of the plate with the imprezsion element thereagainst and compensates for the varying thickness of the plate by displacing in accordance therewith, and where the material is displaced on the printing press it compensates for inaccuracies or irregularities of the press, plate base, and press packing. The displaced material forms a seat for the plate for printing therefrom and in displaced form is resilient and provides a resilient yielding printing contact. y

'lhe material as prepared does not need softening under ordinary circumstances but where it is desired to soften the material slightly aA softening agent may be used such as Water. lVlicre the prepared sheet is used the softening may be effected by applying a sheet of moistened paper to one or both faces of the prepared sheet when the prepared sheet is.applied to the back of the plate.

lVhile I have herein described and shown one embodiment of my invention I do not wish to be limited to the precise details thereof as changes may readily be made Without departingr from the spirit of my invention but having thus described my invention I claim as new and desire to secure by Letters Patent the following:

1. An under-lay for a printing plate or form comprising a displacement space pro; viding pattern of resilient material permanently displaceable under pressure for leveling or building up a printing plate or form and providing in displaced form a resilient seat or backing for the plate :or form.

2. An underlay for a printing plate or form comprising a displacement space providing pattern of resilient material permanentl f displaceable under pressure comprising texibleglue, glycerine, Wax, and water combined in suitable quantities and under suitable conditions.

3. An underlay for a printing plate or form comprising a displacement space providing pattern of resilient material permanently displaceable under pressure comprising four parts of flexible glue, four parts of gylcerine, one half part of paraitine Wax, one half part of rubber cement, and one part of Water boiled together to form the material.

4. An underlay for a. printing plate or form comprising a displacement space providing pattern ofresilient material permanently displaceable under pressure, and' two sheets of suitable protective material adhered to opposite faces of the first mentined material.

An underlay for a printing plate or form comprising a uniform displacement space providing pattern of uniform thickness of resilient material permanently displaceable under pressure and two paper adhered t0 and conforming posite faces of the material.

6. An underlay for a printing plate or form 'comprising a. displacement space providing )attern of resilient material permanentlv c isplaceableunder pressure comprising eXible glue, glycerine, Wax, and Water combined in suitable quantities and under suitable conditions and two sheets of oiled paper adhered to opposite faces of the matcrial and conforming with opposite faces thereof.'

7. An underlay for a printing plate or form comprising a uniform displacement space providing pattern of uniform thicknessof resilient material permanently displaceable under pressure comprising four parts of iexible glue, four parts of glycerine, one half part of parafline Wax, one half part rubber cement, and one part of Water boiled together to fm'm the material and tWo sheets of oiled paper adhered to and conforming with opposite faces of the material.

In Witness whereof I hereunto aliix my signature this sixteenth day of April, 1923.

" SAMUEL E. DITTMAN.

with opsheets of 

